Mixed driving of vehicles



H. PIEPER.

M'HXED DRIVING 0F VEHICLES;

APPLICATION FILED DEC. 22, I913- 1,402,250, Patented Jan. 3,1922.

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' I'H. PIEPER.

MIXE D.DR|VING 0F VEHICLES. APPLICATION FILED DEC.22, 1913.

1,402,250", P wnteman. 3,1922.

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HENRI PIE-PER, 0F LIEGE, BELGIUM.

MIXED DRIVING OF VEHICLES.

Specification of Letters Patent.

Patented Jan. 3, 1922.

Application filed December 22, 1913. Serial No. 808,228.

(GRANTED UNDER THE PROVISIONS OF THE ACT OF MARCH 3, 1921, 41 STAT, L., 1313.)

To all whom it may conccm Be it known that I, HENRI Pinrnn, a subject of the King of Belgium, residing at Liege, Avenue des Thermes 12, in Belgium, have invented certain new and useful Improvements in and Relating to the 'Mixed Driving of Vehicles; and I do hereby declare the following to be a full, clear, and

exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked therein which form a part of this specification.

My invention relates to the mixed driving system, which comprises in combination an explosion or internal combustion engine acting upon the wheels by means of a mechanical power transmission and a dynamo motor which coupled to the heat motor and connected in parallel with a battery serves for buffering and restoring energy.

In the usual embodiment of this driving system the electric machine and the heat engine remain coupled constantly together and this power unit works upon the driving axles by means of a clutch conveniently controlled, but this constant coupling of dynamo-motor and engine entails inconveniences due to the particularities of the mixed driving system: A great part of the energy recuperatedthrough the inertia of the vehicle is wasted in the comparatively great power necessary for the light-running of the explosion engine at the maximum speed. Further, from the standpoint of the total efiiciency of the driving arrangement it seems advantageous to be able to vary the speed reduction between the electric machine and the heat motor, without influencing the speed regulation of the dynamo, so as to use the explosion motor in a manner corresponding more. to the particularities of this engine type.

My invention will meet with these and similar requirements peculiar to mixed driving, by providing a speed relation between the heat motor and the dynamo that is variable in convenient steps between a maximum value, allowing a transmisslon of the thermal power with the maximum speed of the namo-motor and heat motor of a mixed system,

Figure 2 shows a modification according to which thisfl'variation is dependent on the current of the storage battery and Figure 3 represents the case of this variation being dependent simultaneously on the battery state and the line profile.

Referring to Figure 1, the dynamo motor is connected at one end, through interposed gearing, with the driving axle 3 by means of the magnetic clutch 2, while the other end ofthe dynamo shaft carries two planetary wheels 4, 5 the inner wheel 6 engaging therewith being arranged on the'shaft of the explosion engine 7 The outer toothed wheel 8 is arranged to be coupled either with the heatfmotor? by means of the mag netic clutch 9 or with the frame 11 of the vehicle by means of the clutch ring 10. A solenoid 12 serves for regulating the fuel inlet to the thermal engine. The controller comprises the resistance 13 for starting the armature of the electric machine 1 and the resistances l4: and 15 for regulating through the contact 16 the dynamo field and the magnetic clutch 2. The ratio between the wheels 4, and 6 is chosen so that on stopping the outer wheel 8 by the clutch ring 10, the power transmission from the engine to the electric machine takes place with the speed reduction 2:1, while on coupling the outer wheel 8 with the heat motor the speed reduction is 1:1. The clutches 10 and 9 are switched in respectively'by means of the contacts 17 and 18 short-circuiting gradually the resistances 19 and 20. The contact 21 and the resistance 22 serve for varying the strengthof the solenoid 12. The battery 23 supplies the current to the different electric circuits.

The arrangement shown in jFigure 1- works in the following manner: Firstly, the heat motor and the electric machine are coupled together by means of the clutch 1O permittinga, great speed of the engine in the case of a small speed of the vehicle, the speed ratio being 2:1 in this case. To this end the controller drum containing the contacts 17, 18, 21 is brought into position I. Now, the main clutch 2 as well as the dynamogmotor. 1 and engine 7, is switched in and the vehicle is started up by means of the controller drum 16 containing the contact in the known manner. At a certain mo- 7 ment of the electric speed regulation, for instance when the controller 16 is in position X, which is indicated to, the watchman -by a, corresponding value of thedischarge current being'read off the amperemeter, the changing overfrom the one to theother speed ratio will be advisable, which is effected by moving the drum containing the contacts17, 18, 21 into position H so that the speed reduction between engine and dynamo-motor is 1:1. If a recuperation of energy takes place, fo instance on descendmg inclines, both the clutches Sand 10 can be. switched 'out by bringing the controller drum carrylng the contacts 17, 18, 21int-o position 111. At the sametime, the gas admission is reduced, the

contact 21 short-circuiting the resistances 22 regulating the current of the solenoid 12. Consequently the heat motor runs idly withouttransmitting power at a speed reduced for instance to a tenth of the maximum.

Further, more than two speed ratios may be provided, especially for the period of power transmission of the heat motor.

Finally,.the varying of the speed ratio may be effected so as to apply, for instance on ascending hills, during the whole speed regulation period, while in the caseof the neces; sary driving power decreasing, for instance on running on level the speed ratio 1:1 is employed, the heat motor running preferably at reduced speed and fuel admission.

Figure 2 illustrates an embodiment of the invention in which the varying of the speed ratio is dependent on the battery current. A magnetic clutch 32 is'inserted'between the 30 and the internal combus dynamo-motor tion engine 31, while the magnetic clutch 33' serves for connecting the dynamo motor and engine with the driving axles. The controller 34 comprises the resistances 35, 36, 3,7, servingrespectively for starting of the armature,regulatin r the field of the electric machine and switching in the clutch 33; The

clutch .32 is controlled by a differential relay '38 which is dependent onthe tension and the intensity of the battery current, so as to close, when excited by a charge current of a certain value the circuit of the solenoid 39, which cuts off the magnetic clutch 32 through the resistances 40. At the same time, the magnet 38, which is responsive to the differential action of the series and shunt coils acts in a well known manner'upon the gas admission of the heat motor by opening current of the ance 37. The armature taking discharge current from the battery' etl, the core of the differential magnet 38 keeps the circuit of the solenoid 39 open. Consequently, the circuit of the clutch 32 is closed at and the heat engine 31 is coupled to. the'electric machine 30. At the same time the circuit of the main clutch 33 is closed by meansof the contact 34: and the resistance 36:50 that the power set 30, 31 is connected to the wheels. The controller 341, on its further movement, puts in the resistances 37 diminishing the excitation of the electric machine and thereby increasing the speed ofth'epower set and the 7 vehicle up to the maximum. The differential relay 38 is infiuenced'by the current and the tension of the battery so as to keep open the circuit of the solenoid 39 anchthe gas admission of .tlieengine 31 as lon as the electric machine 30 takes current fii'om the battery. But it closes its contacts and causes the eXit-ation of the solenoid 39 as soon'as a charge current of a certain value is produced by the electric machine, the excited solenoid'39 then opening the circuit of'the clutch 32 so as'to disconnect the engine 31 from the-electric machine 30.

enerally, the internal combustiOn engine will be coupled constantly to the dynamo mot-oron ascending inclines and on starting so as to transmitfpower to the driving wheels with the speed ratio for insoance of 1: 1 but .it is disconnected from the electric machine automatically in the case of an energy being" restored up in the battery by the dynamo on descending lnlls and on stopping above I 7 preferably after the charge current having attained acertain small value necessary. for

compensating the electric losses. Simultaneously with the-opening of the clutch 32tl1e fuel admissiont'othe engine 31 is cutoif'by-the magnet 38in a manner that the same runs noirwithout load at a reduced speed or is stopped. Whenjthe vehicle requires vagain driving power so as to provoke a discharge of the battery,',-foi" instance'on starting,-th'e1relay 3'8 closes again the clutch 32 by cutting off the circuit of the solenoid 39 and ire-opens at the same time com letely the gas admission to the engine. ionsequently the thermal and the electric engine are coupled again together soas to furnish power as a single unity to the wheels.

As it is clear from the-foregoing description, a driving system according to my invention permits to obtain an eflicient recuperation of the energy given through the inertia of thevehicle mass on descending inclines or on stopping. A large proportion of this mechanical energy is re-transformed in electrical energy stored up inthe battery, because the loss of the energy is avoided which is otherwise due to the necessityof driving the explosion engine running without load at a great speed. The disconnecting of the heat motor takes place withoutany inconvenience as regards the quiet running of the vehicle, the electric machine constituting a power being constantly coupled to the wheels during the driving period so as to prevent a shock at the moment of disconnecting the heat motor from the wheels. Further the fuel consumption :required by the explosion engine for light running is exceedingly small so as not to represent practically a loss.

Of course, if it is desired the separate disconnecting of the heat motor may be executed at the moment of the discharge current falling below a certain value or becoming zero, for instance on running on the level. Further, the switching in and out of the clutch inserted between the two machines be effected by the driver regulating by hand the speed ratio between dynamo-motor and heatengine. The possibility of disconnecting the explosion engine from the electric machine is advanta eous also in the case where for any reason the heat motor ceases to supply power, so that the electric machine alone has to drive the vehicle. 0

Figure 3 shows an embodiment of the invention, in which the varying of the speed ratio is dependent simultaneously on the pro- 7 file of the line and on the current of the batterye Besides the equipment already shown in Figure 2, there is a second relay 42 controlling the circuit of the solenoid 39. This relay 42 is excited so'as to close its contacts as soon as the mercury interrupting device 43, which takes always the same inclination as that of the vehicle frame closes the contacts 44 or 45 respectively according to the sense of running in the case of descending inclines of a certain angle. If, at

the same time, the battery current attains a fixed amount, the relay 38 closes also its contacts. Consequentl the circuit of the solenoid 39 is completely closed and the disconnection of the clutch 32 takes place. Preferably, the heat motor is then brought to a reduced speed or to standstill by regulating suitably the fuel inlet. The one of the clare what I claim as new and desire to secure by Letters Patent is:

1. A driving system for self-propelled vehicles comprising in combination a dynamo electric machine, a battery connected there to, a clutch coupling said electric machine to the wheels, an internal combustion engine,

an adjustable clutch inserted between said engine and said electric machine and enabling said engine to work without load at a conveniently reduced speed, means for controlling the speed of said electric machine, an automatic device dependent on the voltage and the strength of the battery current and controlling said adjustable clutch, and automatic means for varying the gas admission to said engine dependent upon the electric state of the battery. 7

2. A driving system for self-propelled vehicles comprising in combination a dynamo electric machine, a battery connected there to, a clutch coupling said electric machine to the wheels, an internal combustion engine, an adjustable clutch inserted between said engine and said electric machine, means for controlling the speed of said electric machine, an automatic device dependent on the gradient and controlling said adjustable clutch, and automatic means for reducing the speed of said engine up to standstill.

3. A driving system for self-propelled vehicles comprising in combination a dynamo electric machine, a battery connected thereto, a clutch coupling said electric machine to the wheels, an internal combustion engine, an adjustable clutch inserted between said two machines and allowing said engine to transmit power to the wheels or to work without load at a conveniently reduced speed respectively, an automatic device dependent upon the electric state of the battery and the gradient and controlling said adjustable clutch, and means for varyin the gas admission to said engine depen ent upon the amperage and the voltage of the battery current.

4:. A driving system for self-propelled vehicles comprising in combination an internal combustion engine, a dynamo electric machine, a battery connected to the latter, a clutch coupling said electric machine to the wheels, an adjustable clutch inserted between said two machines, a controller for regulating the speed of said electric machine, an automatic device for varying the gas admission of said engine dependent upon the battery charging current, and automatic means controllin said adjustable clutch so as to cut off said engine from said electric Vn'iachine, in the event of the charging current exceeding acertain value, and to reestal'olish the coupling if'the charging-current sinks b'elon thi'sv'alue.

5. A driving system for self-propelled vehicles comprlsing in combination a dynamo electric machine coupled to the wheels, a

battery connected to said electric machine,

an internal combustion engine, means for coupling or disconnecting respectively said engine and said electric machlne, a controller for regulating the speed of said electric machine, an automatic device dependent upon the electric state of the battery and varying the gas admission to said engine,

and automatic means controlling said cou-. phng means dependent upon the gradient'so as to disconnect said engine only on descending lncllnes of an angle exceeding a certain value.

6. A driving system comprising in combi-' nation a dynamo electric'machine a battery connected thereto, an electromagnetic clutch coupling said electric machine to the Wheels, a controller for regulating said clutch and for varying the speed of said electric 'ma chine, an internal coinhustion'e'ngine, an'aur tomatic device dependent u on the electric state or the battery old-regulating the gas admission to said engine, an adjustable clutch inserted between said-two machines andenabling said engine to" transmit power In testimony WhereofI aflix my signature in presence of two Witnesses.

, ENRI Pi'E PERf Witnesses:

EM. HEPLIN, A. 

